An objective of a fuel injector is to accurately deliver fuel to an associated engine or combustion chamber. A control valve controls the injection start and finish by controlling the intake channel of an injection pump. The control valve is provided with a valve body which is in the form of a piston valve and is provided with a valve seat, with a high pressure chamber and a low pressure chamber, respectively, being provided on the two sides of the valve seat. To deliver the predetermined correct quantity of fuel for each combustion event, it is expected that the valve will open and then close precisely.
It is desirable to restrict the movement of the top external o-ring to prevent the o-ring from falling out of the injector during later stages of injector assembly, test, packaging and shipping, as well as during engine assembly and engine servicing. In some current injectors, a retainer is molded simultaneously with the injector body mold. The retainer is used to restrict the movement of the top external o-ring in providing a static seal between the injector and the fuel rail assembly. The retainer is molded around the inlet tube at the top of the injector. Unfortunately, various problems with production mold flash have created a need for a design alternative for the retainer. Once such alternative is to use a metal retainer which is crimped after installation. However, the design and assembly processes of certain injectors types do not readily allow such crimping operation.
It is seen then that there exists a need for a retainer for a fuel injector which is flexible for installation and robust for injector application.